/*****************************************************************************/
/* SAttrFile.cpp                          Copyright (c) Ladislav Zezula 2007 */
/*---------------------------------------------------------------------------*/
/* Description:                                                              */
/*---------------------------------------------------------------------------*/
/*   Date    Ver   Who  Comment                                              */
/* --------  ----  ---  -------                                              */
/* 12.06.04  1.00  Lad  The first version of SAttrFile.cpp                   */
/*****************************************************************************/

#define __STORMLIB_SELF__
#include "StormLib.h"
#include "StormCommon.h"

//-----------------------------------------------------------------------------
// Local structures

typedef struct _MPQ_ATTRIBUTES_HEADER
{
    DWORD dwVersion;                    // Version of the (attributes) file. Must be 100 (0x64)
    DWORD dwFlags;                      // See MPQ_ATTRIBUTE_XXXX

    // Followed by an array of CRC32
    // Followed by an array of file times
    // Followed by an array of MD5
    // Followed by an array of patch bits

    // Note: The MD5 in (attributes), if present, is a hash of the entire file.
    // In case the file is an incremental patch, it contains MD5 of the file
    // after being patched.

} MPQ_ATTRIBUTES_HEADER, *PMPQ_ATTRIBUTES_HEADER;

//-----------------------------------------------------------------------------
// Local functions

static DWORD GetSizeOfAttributesFile(DWORD dwAttrFlags, DWORD dwBlockTableSize)
{
    DWORD cbAttrFile = sizeof(MPQ_ATTRIBUTES_HEADER);

    // Calculate size of the (attributes) file
    if(dwAttrFlags & MPQ_ATTRIBUTE_CRC32)
        cbAttrFile += dwBlockTableSize * sizeof(DWORD);
    if(dwAttrFlags & MPQ_ATTRIBUTE_FILETIME)
        cbAttrFile += dwBlockTableSize * sizeof(ULONGLONG);
    if(dwAttrFlags & MPQ_ATTRIBUTE_MD5)
        cbAttrFile += dwBlockTableSize * MD5_DIGEST_SIZE;

    // The bit array has been created without the last bit belonging to (attributes)
    // When the number of files is a multiplier of 8 plus one, then the size of (attributes)
    // if 1 byte less than expected.
    // Example: wow-update-13164.MPQ: BlockTableSize = 0x62E1, but there's only 0xC5C bytes
    if(dwAttrFlags & MPQ_ATTRIBUTE_PATCH_BIT)
        cbAttrFile += (dwBlockTableSize + 6) / 8;

    return cbAttrFile;
}

static DWORD CheckSizeOfAttributesFile(DWORD cbAttrFile, DWORD dwAttrFlags, DWORD dwBlockTableSize)
{
    DWORD cbHeaderSize = sizeof(MPQ_ATTRIBUTES_HEADER);
    DWORD cbChecksumSize1 = 0;
    DWORD cbChecksumSize2 = 0;
    DWORD cbFileTimeSize1 = 0;
    DWORD cbFileTimeSize2 = 0;
    DWORD cbFileHashSize1 = 0;
    DWORD cbFileHashSize2 = 0;
    DWORD cbPatchBitSize1 = 0;
    DWORD cbPatchBitSize2 = 0;
    DWORD cbPatchBitSize3 = 0;

    //
    // Various variants with the patch bit
    //
    // interface.MPQ.part from WoW build 10958 has
    // the MPQ_ATTRIBUTE_PATCH_BIT set, but there's an array of DWORDs instead.
    // The array is filled with zeros, so we don't know what it should contain
    //
    // Zenith.SC2MAP has the MPQ_ATTRIBUTE_PATCH_BIT set, but the bit array is missing
    //
    // Elimination Tournament 2.w3x's (attributes) have one entry less
    //
    // There may be two variants: Either the (attributes) file has full
    // number of entries, or has one entry less
    //

    // Get the expected size of CRC32 array
    if(dwAttrFlags & MPQ_ATTRIBUTE_CRC32)
    {
        cbChecksumSize1 += dwBlockTableSize * sizeof(DWORD);
        cbChecksumSize2 += cbChecksumSize1 - sizeof(DWORD);
    }

    // Get the expected size of FILETIME array
    if(dwAttrFlags & MPQ_ATTRIBUTE_FILETIME)
    {
        cbFileTimeSize1 += dwBlockTableSize * sizeof(ULONGLONG);
        cbFileTimeSize2 += cbFileTimeSize1 - sizeof(ULONGLONG);
    }

    // Get the expected size of MD5 array
    if(dwAttrFlags & MPQ_ATTRIBUTE_MD5)
    {
        cbFileHashSize1 += dwBlockTableSize * MD5_DIGEST_SIZE;
        cbFileHashSize2 += cbFileHashSize1 - MD5_DIGEST_SIZE;
    }

    // Get the expected size of patch bit array
    if(dwAttrFlags & MPQ_ATTRIBUTE_PATCH_BIT)
    {
        cbPatchBitSize1 =
        cbPatchBitSize2 = ((dwBlockTableSize + 6) / 8);
        cbPatchBitSize3 = dwBlockTableSize * sizeof(DWORD);
    }

    // Check if the (attributes) file entry count is equal to our file table size
    if(cbAttrFile == (cbHeaderSize + cbChecksumSize1 + cbFileTimeSize1 + cbFileHashSize1 + cbPatchBitSize1))
        return dwBlockTableSize;

    // Check if the (attributes) file entry count is equal to our file table size minus one
    if(cbAttrFile == (cbHeaderSize + cbChecksumSize2 + cbFileTimeSize2 + cbFileHashSize2 + cbPatchBitSize2))
        return dwBlockTableSize - 1;

    // Zenith.SC2MAP has the MPQ_ATTRIBUTE_PATCH_BIT set, but the bit array is missing
    if(cbAttrFile == (cbHeaderSize + cbChecksumSize1 + cbFileTimeSize1 + cbFileHashSize1))
        return dwBlockTableSize;

    // interface.MPQ.part (WoW build 10958) has the MPQ_ATTRIBUTE_PATCH_BIT set
    // but there's an array of DWORDs (filled with zeros) instead of array of bits
    if(cbAttrFile == (cbHeaderSize + cbChecksumSize1 + cbFileTimeSize1 + cbFileHashSize1 + cbPatchBitSize3))
        return dwBlockTableSize;

#ifdef __STORMLIB_TEST__
    // Invalid size of the (attributes) file
    // Note that many MPQs, especially Warcraft III maps have the size of (attributes) invalid.
    // We only perform this check if this is the STORMLIB testprogram itself
//  assert(false);
#endif

    return 0;
}

static int LoadAttributesFile(TMPQArchive * ha, LPBYTE pbAttrFile, DWORD cbAttrFile)
{
    LPBYTE pbAttrFileEnd = pbAttrFile + cbAttrFile;
    LPBYTE pbAttrPtr = pbAttrFile;
    DWORD dwAttributesEntries = 0;
    DWORD i;

    // Load and verify the header
    if((pbAttrPtr + sizeof(MPQ_ATTRIBUTES_HEADER)) <= pbAttrFileEnd)
    {
        PMPQ_ATTRIBUTES_HEADER pAttrHeader = (PMPQ_ATTRIBUTES_HEADER)pbAttrPtr;
        
        // Verify the header version
        BSWAP_ARRAY32_UNSIGNED(pAttrHeader, sizeof(MPQ_ATTRIBUTES_HEADER));
        if(pAttrHeader->dwVersion != MPQ_ATTRIBUTES_V1)
            return ERROR_BAD_FORMAT;

        // Verify the flags
        if(pAttrHeader->dwFlags & ~MPQ_ATTRIBUTE_ALL)
            return ERROR_BAD_FORMAT;

        // Verify whether file size of (attributes) is expected
        dwAttributesEntries = CheckSizeOfAttributesFile(cbAttrFile, pAttrHeader->dwFlags, ha->pHeader->dwBlockTableSize);
        if(dwAttributesEntries == 0)
            return ERROR_BAD_FORMAT;

        ha->dwAttrFlags = pAttrHeader->dwFlags;
        pbAttrPtr = (LPBYTE)(pAttrHeader + 1);
    }

    // Load the CRC32 (if present)
    if(ha->dwAttrFlags & MPQ_ATTRIBUTE_CRC32)
    {
        LPDWORD ArrayCRC32 = (LPDWORD)pbAttrPtr;
        DWORD cbArraySize = dwAttributesEntries * sizeof(DWORD);

        // Verify if there's enough data
        if((pbAttrPtr + cbArraySize) > pbAttrFileEnd)
            return ERROR_FILE_CORRUPT;

        BSWAP_ARRAY32_UNSIGNED(ArrayCRC32, cbCRC32Size);
        for(i = 0; i < dwAttributesEntries; i++)
            ha->pFileTable[i].dwCrc32 = ArrayCRC32[i];
        pbAttrPtr += cbArraySize;
    }

    // Load the FILETIME (if present)
    if(ha->dwAttrFlags & MPQ_ATTRIBUTE_FILETIME)
    {
        ULONGLONG * ArrayFileTime = (ULONGLONG *)pbAttrPtr;
        DWORD cbArraySize = dwAttributesEntries * sizeof(ULONGLONG);

        // Verify if there's enough data
        if((pbAttrPtr + cbArraySize) > pbAttrFileEnd)
            return ERROR_FILE_CORRUPT;

        BSWAP_ARRAY64_UNSIGNED(ArrayFileTime, cbFileTimeSize);
        for(i = 0; i < dwAttributesEntries; i++)
            ha->pFileTable[i].FileTime = ArrayFileTime[i];
        pbAttrPtr += cbArraySize;
    }

    // Load the MD5 (if present)
    if(ha->dwAttrFlags & MPQ_ATTRIBUTE_MD5)
    {
        LPBYTE ArrayMd5 = pbAttrPtr;
        DWORD cbArraySize = dwAttributesEntries * MD5_DIGEST_SIZE;

        // Verify if there's enough data
        if((pbAttrPtr + cbArraySize) > pbAttrFileEnd)
            return ERROR_FILE_CORRUPT;

        for(i = 0; i < dwAttributesEntries; i++)
        {
            memcpy(ha->pFileTable[i].md5, ArrayMd5, MD5_DIGEST_SIZE);
            ArrayMd5 += MD5_DIGEST_SIZE;
        }
        pbAttrPtr += cbArraySize;
    }

    // Read the patch bit for each file (if present)
    if(ha->dwAttrFlags & MPQ_ATTRIBUTE_PATCH_BIT)
    {
        LPBYTE pbBitArray = pbAttrPtr;
        DWORD cbArraySize = (dwAttributesEntries + 7) / 8;
        DWORD dwByteIndex = 0;
        DWORD dwBitMask = 0x80;

        // Verify if there's enough data
        if((pbAttrPtr + cbArraySize) == pbAttrFileEnd)
        {
            for(i = 0; i < dwAttributesEntries; i++)
            {
                ha->pFileTable[i].dwFlags |= (pbBitArray[dwByteIndex] & dwBitMask) ? MPQ_FILE_PATCH_FILE : 0;
                dwByteIndex += (dwBitMask & 0x01);
                dwBitMask = (dwBitMask << 0x07) | (dwBitMask >> 0x01);
            }
        }
    }

    return ERROR_SUCCESS;
}

static LPBYTE CreateAttributesFile(TMPQArchive * ha, DWORD * pcbAttrFile)
{
    PMPQ_ATTRIBUTES_HEADER pAttrHeader;
    TFileEntry * pFileTableEnd = ha->pFileTable + ha->pHeader->dwBlockTableSize;
    TFileEntry * pFileEntry;
    LPBYTE pbAttrFile;
    LPBYTE pbAttrPtr;
    size_t cbAttrFile;

    // Check if we need patch bits in the (attributes) file
    for(pFileEntry = ha->pFileTable; pFileEntry < pFileTableEnd; pFileEntry++)
    {
        if(pFileEntry->dwFlags & MPQ_FILE_PATCH_FILE)
        {
            ha->dwAttrFlags |= MPQ_ATTRIBUTE_PATCH_BIT;
            break;
        }
    }

    // Allocate the buffer for holding the entire (attributes)
    // Allocate 1 byte more (See GetSizeOfAttributesFile for more info)
    cbAttrFile = GetSizeOfAttributesFile(ha->dwAttrFlags, ha->pHeader->dwBlockTableSize);
    pbAttrFile = pbAttrPtr = STORM_ALLOC(BYTE, cbAttrFile + 1);
    if(pbAttrFile != NULL)
    {
        // Make sure it's all zeroed
        memset(pbAttrFile, 0, cbAttrFile + 1);

        // Write the header of the (attributes) file
        pAttrHeader = (PMPQ_ATTRIBUTES_HEADER)pbAttrPtr;
        pAttrHeader->dwVersion = BSWAP_INT32_UNSIGNED(100);
        pAttrHeader->dwFlags   = BSWAP_INT32_UNSIGNED((ha->dwAttrFlags & MPQ_ATTRIBUTE_ALL));
        pbAttrPtr = (LPBYTE)(pAttrHeader + 1);

        // Write the array of CRC32, if present
        if(ha->dwAttrFlags & MPQ_ATTRIBUTE_CRC32)
        {
            LPDWORD pArrayCRC32 = (LPDWORD)pbAttrPtr;

            // Copy from file table
            for(pFileEntry = ha->pFileTable; pFileEntry < pFileTableEnd; pFileEntry++)
                *pArrayCRC32++ = BSWAP_INT32_UNSIGNED(pFileEntry->dwCrc32);

            // Update pointer
            pbAttrPtr = (LPBYTE)pArrayCRC32;
        }

        // Write the array of file time
        if(ha->dwAttrFlags & MPQ_ATTRIBUTE_FILETIME)
        {
            ULONGLONG * pArrayFileTime = (ULONGLONG *)pbAttrPtr;

            // Copy from file table
            for(pFileEntry = ha->pFileTable; pFileEntry < pFileTableEnd; pFileEntry++)
                *pArrayFileTime++ = BSWAP_INT64_UNSIGNED(pFileEntry->FileTime);

            // Update pointer
            pbAttrPtr = (LPBYTE)pArrayFileTime;
        }

        // Write the array of MD5s
        if(ha->dwAttrFlags & MPQ_ATTRIBUTE_MD5)
        {
            LPBYTE pbArrayMD5 = pbAttrPtr;

            // Copy from file table
            for(pFileEntry = ha->pFileTable; pFileEntry < pFileTableEnd; pFileEntry++)
            {
                memcpy(pbArrayMD5, pFileEntry->md5, MD5_DIGEST_SIZE);
                pbArrayMD5 += MD5_DIGEST_SIZE;
            }

            // Update pointer
            pbAttrPtr = pbArrayMD5;
        }

        // Write the array of patch bits
        if(ha->dwAttrFlags & MPQ_ATTRIBUTE_PATCH_BIT)
        {
            LPBYTE pbBitArray = pbAttrPtr;
            DWORD dwByteIndex = 0;
            BYTE dwBitMask = 0x80;

            // Copy from file table
            for(pFileEntry = ha->pFileTable; pFileEntry < pFileTableEnd; pFileEntry++)
            {
                // Set the bit, if needed
                if(pFileEntry->dwFlags & MPQ_FILE_PATCH_FILE)
                    pbBitArray[dwByteIndex] |= dwBitMask;

                // Update bit index and bit mask
                dwByteIndex += (dwBitMask & 0x01);
                dwBitMask = (dwBitMask << 0x07) | (dwBitMask >> 0x01);
            }

            // Move past the bit array
            pbAttrPtr += (ha->pHeader->dwBlockTableSize + 6) / 8;
        }

        // Now we expect that current position matches the estimated size
        // Note that if there is 1 extra bit above the byte size,
        // the table is actually 1 byte shorter in Blizzard MPQs. See GetSizeOfAttributesFile
        assert((size_t)(pbAttrPtr - pbAttrFile) == cbAttrFile);
    }

    // Give away the attributes file
    if(pcbAttrFile != NULL)
        *pcbAttrFile = (DWORD)cbAttrFile;
    return pbAttrFile;
}

//-----------------------------------------------------------------------------
// Public functions (internal use by StormLib)

int SAttrLoadAttributes(TMPQArchive * ha)
{
    HANDLE hFile = NULL;
    LPBYTE pbAttrFile;
    DWORD dwBytesRead;
    DWORD cbAttrFile = 0;
    int nError = ERROR_FILE_CORRUPT;

    // File table must be initialized
    assert(ha->pFileTable != NULL);
    assert((ha->dwFlags & MPQ_FLAG_BLOCK_TABLE_CUT) == 0);

    // Don't load the attributes file from malformed Warcraft III maps
    if(ha->dwFlags & MPQ_FLAG_MALFORMED)
        return ERROR_FILE_CORRUPT;

    // Attempt to open the "(attributes)" file.
    if(SFileOpenFileEx((HANDLE)ha, ATTRIBUTES_NAME, SFILE_OPEN_ANY_LOCALE, &hFile))
    {
        // Retrieve and check size of the (attributes) file
        cbAttrFile = SFileGetFileSize(hFile, NULL);
        
        // Integer overflow check
        if((cbAttrFile + 1) > cbAttrFile)
        {
            // Size of the (attributes) might be 1 byte less than expected
            // See GetSizeOfAttributesFile for more info
            pbAttrFile = STORM_ALLOC(BYTE, cbAttrFile + 1);
            if(pbAttrFile != NULL)
            {
                // Set the last byte to 0 in case the size should be 1 byte greater
                pbAttrFile[cbAttrFile] = 0;

                // Load the entire file to memory
                SFileReadFile(hFile, pbAttrFile, cbAttrFile, &dwBytesRead, NULL);
                if(dwBytesRead == cbAttrFile)
                    nError = LoadAttributesFile(ha, pbAttrFile, cbAttrFile);

                // Free the buffer
                STORM_FREE(pbAttrFile);
            }
        }

        // Close the attributes file
        SFileCloseFile(hFile);
    }

    return nError;
}

// Saves the (attributes) to the MPQ
int SAttrFileSaveToMpq(TMPQArchive * ha)
{
    TMPQFile * hf = NULL;
    LPBYTE pbAttrFile;
    DWORD cbAttrFile = 0;
    int nError = ERROR_SUCCESS;

    // Only save the attributes if we should do so
    if(ha->dwFileFlags2 != 0)
    {
        // At this point, we expect to have at least one reserved entry in the file table
        assert(ha->dwFlags & MPQ_FLAG_ATTRIBUTES_NEW);
        assert(ha->dwReservedFiles > 0);

        // Create the raw data that is to be written to (attributes)
        // Note: Blizzard MPQs have entries for (listfile) and (attributes),
        // but they are filled empty
        pbAttrFile = CreateAttributesFile(ha, &cbAttrFile);
        if(pbAttrFile != NULL)
        {
            // Determine the real flags for (attributes)
            if(ha->dwFileFlags2 == MPQ_FILE_EXISTS)
                ha->dwFileFlags2 = GetDefaultSpecialFileFlags(cbAttrFile, ha->pHeader->wFormatVersion);

            // Create the attributes file in the MPQ
            nError = SFileAddFile_Init(ha, ATTRIBUTES_NAME,
                                           0,
                                           cbAttrFile,
                                           LANG_NEUTRAL,
                                           ha->dwFileFlags2 | MPQ_FILE_REPLACEEXISTING,
                                          &hf);

            // Write the attributes file raw data to it
            if(nError == ERROR_SUCCESS)
            {
                // Write the content of the attributes file to the MPQ
                nError = SFileAddFile_Write(hf, pbAttrFile, cbAttrFile, MPQ_COMPRESSION_ZLIB);
                SFileAddFile_Finish(hf);
            }

            // Clear the number of reserved files
            ha->dwFlags &= ~(MPQ_FLAG_ATTRIBUTES_NEW | MPQ_FLAG_ATTRIBUTES_NONE);
            ha->dwReservedFiles--;

            // Free the attributes buffer
            STORM_FREE(pbAttrFile);
        }
        else
        {
            // If the (attributes) file would be empty, its OK
            nError = (cbAttrFile == 0) ? ERROR_SUCCESS : ERROR_NOT_ENOUGH_MEMORY;
        }
    }
    
    return nError;
}

//-----------------------------------------------------------------------------
// Public functions

DWORD WINAPI SFileGetAttributes(HANDLE hMpq)
{
    TMPQArchive * ha = (TMPQArchive *)hMpq;

    // Verify the parameters
    if(!IsValidMpqHandle(hMpq))
    {
        SetLastError(ERROR_INVALID_PARAMETER);
        return SFILE_INVALID_ATTRIBUTES;
    }

    return ha->dwAttrFlags;
}

bool WINAPI SFileSetAttributes(HANDLE hMpq, DWORD dwFlags)
{
    TMPQArchive * ha = (TMPQArchive *)hMpq;

    // Verify the parameters
    if(!IsValidMpqHandle(hMpq))
    {
        SetLastError(ERROR_INVALID_PARAMETER);
        return false;
    }

    // Not allowed when the archive is read-only
    if(ha->dwFlags & MPQ_FLAG_READ_ONLY)
    {
        SetLastError(ERROR_ACCESS_DENIED);
        return false;
    }

    // Set the attributes
    InvalidateInternalFiles(ha);
    ha->dwAttrFlags = (dwFlags & MPQ_ATTRIBUTE_ALL);
    return true;
}

bool WINAPI SFileUpdateFileAttributes(HANDLE hMpq, const char * szFileName)
{
    hash_state md5_state;
    TMPQArchive * ha = (TMPQArchive *)hMpq;
    TMPQFile * hf;
    BYTE Buffer[0x1000];
    HANDLE hFile = NULL;
    DWORD dwTotalBytes = 0;
    DWORD dwBytesRead;
    DWORD dwCrc32;

    // Verify the parameters
    if(!IsValidMpqHandle(ha))
    {
        SetLastError(ERROR_INVALID_PARAMETER);
        return false;
    }

    // Not allowed when the archive is read-only
    if(ha->dwFlags & MPQ_FLAG_READ_ONLY)
    {
        SetLastError(ERROR_ACCESS_DENIED);
        return false;
    }

    // Attempt to open the file
    if(!SFileOpenFileEx(hMpq, szFileName, SFILE_OPEN_BASE_FILE, &hFile))
        return false;

    // Get the file size
    hf = (TMPQFile *)hFile;
    dwTotalBytes = hf->pFileEntry->dwFileSize;

    // Initialize the CRC32 and MD5 contexts
    md5_init(&md5_state);
    dwCrc32 = crc32(0, Z_NULL, 0);

    // Go through entire file and calculate both CRC32 and MD5
    while(dwTotalBytes != 0)
    {
        // Read data from file
        SFileReadFile(hFile, Buffer, sizeof(Buffer), &dwBytesRead, NULL);
        if(dwBytesRead == 0)
            break;

        // Update CRC32 and MD5
        dwCrc32 = crc32(dwCrc32, Buffer, dwBytesRead);
        md5_process(&md5_state, Buffer, dwBytesRead);

        // Decrement the total size
        dwTotalBytes -= dwBytesRead;
    }

    // Update both CRC32 and MD5
    hf->pFileEntry->dwCrc32 = dwCrc32;
    md5_done(&md5_state, hf->pFileEntry->md5);

    // Remember that we need to save the MPQ tables
    InvalidateInternalFiles(ha);
    SFileCloseFile(hFile);
    return true;
}
